Lay two planks of 76-inch 1-by-2 lumber flat on your work table with 36 inches between these. Fit two planks of 36-inch 1-by-2 lumber between the ends of the 76-inch planks to make a rectangular frame.
Glue the frame together and let dry. Drill two pilot holes through the 76-inch planks into the ends of the 36-inch planks and secure the frame together with 2 1/2-inch wood screws through the pilot holes. The frame will measure 40-by-76 inches around the outside.
Place a sheet of 1/2-inch plywood measuring 40-by-76 inches over the top of the frame. Secure the plywood in place with 3/4-inch screws driven every 6 to 8 inches around the perimeter.
Spray the plywood with spray adhesive, as well as one side of a 40-by-76 inch piece of 2-inch thick foam, then press the foam onto the plywood to secure it in place.
Lay out a piece of faux leather measuring approximately 50-by-86 inches, wrong side up. Place the headboard frame on top, with the foam side down.
Pull the faux leather up over the sides of the headboard frame and pin it to the back of the frame, starting from the middle of each side of the frame, working outward. Fold the corners as you would when wrapping a box present.
Turn the frame over and examine the faux leather from the front. If any areas are pulled too tight, or not tight enough, adjust the pinning at the back.
Turn the headboard frame back over once you are satisfied with the faux leather positioning, then staple the leather in place and remove the pins. Trim the excess material with scissors.
Mark a line above the bed, approximately 38 inches up from the mattress height. Use a level to ensure that the line is straight. Locate the wall studs on the line with a stud finder and mark each stud's position.
Place a piece of 72-inch 1-by-2 lumber centered on the wall line. This is the cleat for attaching the headboard. Secure the cleat with two 3-inch screws driven through each of the stud positions.
Lift the headboard up to the wall and fit it over the cleat. The 1-by-2 frame at the back of the headboard should sit on top of the cleat, with the headboard flush against the wall. Secure the headboard in place with 3-inch screws through the top edge of the headboard into the cleat.